Google SEO News and Discussion Forum

I can't find any 'official' advice from Google on how best to handle redirects for mobile users who access the desktop version of a URL, and then are redirected to the corresponding mobile version of the same page.

If you're redirecting based on user-agent or browser capabilities, then it is an inherently temporary redirect. You need visitors to land on your redirect URL so that you can ascertain which version to browse to.

A concrete example - if I emailed a link to a friend, would I prefer it to be the page that works out if I'm mobile or not, or a device-specific version? I don't know the technology that will be used, so I would prefer the former.

So for me, it's a 302 every time (possibly 307) which tells the user-agent to request the original URL.

Yeah - I guess the argument here is that for that user-agent, the permanent location is the mobile version. Doesn't make good technical sense to me though. It also raises a few question about having a separate mobile and desktop search index - presumably that means an entirely different link map for mobile content.

Still, if Google says that's the way they want it, then serving googlebot-mobile a 301 is the way to go.

This is a good discussion - worth more attention, I'd say. My own feeling is that serving a mobile site on a dedicated hostname is not what the original W3C vision was. Their idea is to serve different CSS files based on the user-agent.

That would certainly make any redirect questions irrelevant. But I can't get past the idea that even with serving an appropriate CSS for mobile browser file, you'd still be serving a lot of unneeded code to a mobile browser. With mobile connectivity and bandwidth challenges very much with us, I'm still more comfortable with a dedicated hostname and a redirect.

Google assures us that a 301 redirect for mobile user agents is what they will deal with most effectively, and I haven't heard any contrary reports.

301 works almost well. Dekstop version of Google won't list mobile URLs, and mobile version marks them as mobile-friendly. But WMT throws "When we tested a sample of URLs from your Sitemap, we found that some URLs redirect to other locations. HTTP Error: 301" for mobile sitemap.

Thanks for this guys. I've just been through a similar process with a client and upon checking it's currently using a 302 redirect. At present it doesn't seem to be having any detrimental effect but I'll ensure it's changed to a 301 to comply with Googles guidelines. Thanks for the link @Scott_Mc!

301 or 302, I asked Matt Cutts which to use at SMX West last month. He was not able to give me a clear answer at that time. He told me he would ask the question to the right team. But I'm sorry I have no idea how to get the answer from him. :(

The link Scott_Mc offered in the third post is to a recent official Google blog article that recommends a 301 for mobile users who request the desktop version - that includes the googlebot-mobile crawler.

The article is from Feb 2011 - I'd consider that to be the current official word on the type of redirect. The technical challenge (and gray area) is recognizing all the mobile user-agents properly.

The technical challenge (and gray area) is recognizing all the mobile user-agents properly.

Agreed! If you do go down the 301 route (which I have reconsidered since my previous comment) you certainly need to ensure you do not accidentally 301 any non-mobile crawlers to the mobile domain/sub-domain! Identifying all mobile user agents if one hell of a task so if anyone has any ideas/resources please share!

I'm gonna stick with the 302 for the time being as it seems to be functioning adequately - "if it's not broken don't fix it" as they say! I'll check back with an update in a couple of weeks.